The present invention relates generally to implant assemblies that include an interbody implant engaged to an extradiscal support plate, and to methods and systems for inserting one or more spinal implant assemblies with support plates.
Several techniques and systems have been developed for correcting and stabilizing the spine and for facilitating fusion at various levels of the spine. The spinal anatomy including the bony structure of vertebral bodies, vascular structures, neural structures, musculature, and other vital tissue along the spinal column make it difficult to position an interbody implant in the disc space between adjacent vertebral bodies or to engage a plate between the adjacent vertebrae. In addition, when an implant is placed into a disc space, the channel or path that the implant took to enter the disc space provides a path for retrograde movement of the implant from the disc space. The variability in the location of the trailing end of the implant relative to the adjacent vertebral bodies can make attaching a plate to the implant and to the adjacent vertebral bodies difficult to achieve.
Correction of deformities from approaches that parallel or extend substantially parallel to the sagittal plane is difficult to achieve with an interbody implant due to the intervening anatomy. Surface area contact between the implant and the hard cortical bone of the endplate can be too small so that the implant subsides too much and tends to want to break through the endplates. Unilateral fixation is not always an option because of stability issues of a narrow implant. While a lateral approach to the disc space avoids certain critical anatomical structures that impede access in other approaches, the ability to insert an implant through a small or minimally invasive portal and achieve the desired support in the disc space from a lateral approach is challenging. As a result, additional improvements in spinal fusion implants and insertion instruments and techniques are needed that make utilization of a lateral approach more palatable, although utilization of such implants and instrument is not necessarily limited to a lateral approach.